roadmap

[Ray Plante]

On Wed, 10 Mar 2004, Tony Linde wrote:
> Has the NVO project (or anyone else) built or prototyped any way in which
> users can submit a registry query (in whatever form) and have the resultant
> services (even if only data services) automatically invoked?

The NVO Data Invetory service 
(http://heasarc.gsfc.nasa.gov/vo/data-inventory.html) does just this.  
Given a position in the sky, the registry is queried via a web service 
requesting SIA and ConeSearch services.  These are then invoked to 
determine what data is available at the given position.

> - including
> AstroGrid data services, VizieR services etc? 

In theory, there is sufficient metadata to query GLU-registered services, 
but we have not yet tested this.  We also could, in principle, 
automatically invoke traditional, arbitrary GET HTTP services; how 
practical this is depends on the how sufficiently describable the output 
is.  Web services can also be registered; accessing these should be 
trivial, but we don't have an demonstration involving the registry, yet.  
This will likely change this spring with the growing work on SkyNode.  

Do AstroGrid services fall into any of the above catagories?  Part of 
automatically invoking a service effectively is making use of the 
Capability metadata, which (as you recall) are specific for a particular 
type of "standard" service.  You could consider defining a set of 
capability metadata for AstroGrid services, similar to SIA-v0.X.xsd and 
ConeSearch-v0.X.xsd.

> If so, can you point us to it
> - would help to be able to see how this works.

I think we can provide more information about how DIS uses the resource 
metadata to choose and invoke its service if need be.  I don't know if 
these specifics are published anywhere at the moment.  

cheers,
Ray